Autoloading firearm



@et 6, 1942. A. A. DlcKE AUTOLOADING FIREARM Filed Nov. 2, 1940 5Sheets-Sheet 1 Get., 6, 1942. A. A. DlcKE AUTOLOADING FIREARM Filed Nov.2, 1940 3 Sheets-Sheet 2 .iwi WNW mwmw @M im i..

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'INVENTOR //n Waffe ATTORNEY Patented Oct. i942 UNITED STATES PATENTOFFICE AUToLoAnING FmEAaM AllenA. Dicke, Montclair, N. I.

Application Novemberl 2, 1940, Serial No. 363,961

Y 1s claims. (c1. .lzmf -This invention relates to autoloading ilrearmswhether of the small arms type such as automatic pistols, autoloadingriiles, sub-machine guns, or machine guns, or of the larger typegenerally designated as ordnance, and has for an object to improve suchdevices bygassuring that against axial or rotary movement), thereby prekventing opening 'of the breech mechanism until the gas pressure hasdropped to a certain point.

A more specic object is to provide such a construction in which thesupporting collar is the connected breech block being temporarily heldin position against such axial movement.

Another object is to provide a device in which the enclosing collar isnormally held against axial movement but is free to rotate, said collarbeing provided with an abutment co-acting with an axially movablenon-rotatable breech block by means of lugs or interrupted threadsthereon, or equivalent co-acting means, whereby the block is held inclosed position while the gas pressure is suiliciently high so that theexpanded chamber holds the collar against rotation but that when the gaspressure drops and the chamber contracts` the collar is rotated throughrearward axial movement of the breech block.

Another object of the invention is to providea device `in which theenclosing collar is normally held against axial movement but is free torotate, said collar being provided with a rearward extension engagingwith a rotatable breech bolt so that rotation and opening of the breechbolt is prevented until the gas pressure has dropped to a certain point.

Further objects and advantages of this invention will be apparent fromconsideration@ of the specication as illustrated by the accompanyingdrawings of possible embodiments of the invention, in which drawings:

Fig. l is a longitudinal vertical cross-sectional view of a portion of afirearm illustrating one form the invention may take;

Fig. 2 shows an explosion gas pressure-time for abnormally high pressureand abnormally low pressure cartridges.

Fig. 3 is a horizontal cross-sectional view of a portion of the receiverand barrel parts of andirectly connected with the breech block forlongitudinal movement therewith, said collar and other re'armillustrating the invention;

Fig. 4 is a view, partly in vertical cross-section,

ofthe arm shownin Fig. 3;

Fig. 5 is Aa cross-section taken on the line 5-5 'of F18. 3;

Fig. 6 is a cross-section taken on the line 6-6 of Fig. 3;

Fig. 7 is a cross-'section taken on the line 1-1 of Fig. 4:

Fig. 8 is a vertical cross-sectional vi w of a part of another ilrearmillustrating th invention;

Fig. 9 is a horizontal cross-sectional view of the The barrel Il isshown threaded to the receiver L3 as at llc. In the form shown, thereceiver has a passage I3a which may be either round or rectangular incross-section. within which passage is located for axial movement thebreech block I4 having integrally formed therewith a forwardly extendingcollar lla whichl surrounds and fits rather closely upon the expandibleportion I Ib of the chamber. The breech bloclrilis biased forwardly bymeans ot spring i5 bearing against an abutment, such as the closingscrew 6. It will be seen that when the cartridge l2 is fired, by anysuitable tiring mechanism not illustrated, the gas pressure will riserapidly, as shown in Fig. 2, causing the expandible chamber IIb toexpand slightly (possibly .0005 to .002 inch) gripping the collar Ha andpreventing the opening ofthe breech. This condition continues ntil thegas pressure has dropped to a certain point as, for example, the valueindicated by the line a-a (Fig. 2). When this point is reached (point y)the chamber part i Ib contracts, due to its natural resiliency, andfrees the collar Ida, whereupon the breech block I4 is drivenrearwardly, due to the residual pressure compressing spring l5.

For convenience in electing the red cartridge case, the breech block ispreferably formed as curve of a normal cartridge and similar curvesshown, i. e., the breech block contains a bolt Il Itwill be-noted thatthe closing screw I6 is formedwith a forward extension I6a in lineAwith. the bolt v portion 11b.` Therefore, as th'e breech block I4 isdriven rearwardly-by the remaining .g

against the Abolt l 24'.-` -However, at' the same4 time;V 0;

gas pressure acting through bolt head pl1a, the.

Abolt andblock will move back. together until the fired case hasbeenwithdrawn from the chamber, ,i

(assisted if necessary by extractor I'ld preferably carried by the bolthead Ha). vThereafter, bolt f Y this point is' reached, `the-,chambe'rpart 2'Ibconblock |14 continues to travelto vthe end of its l1 isarrested Vby the extension lia, wh'ereas the movement (the parts now arein the dotted line vposition of Fig. l). `At this time, ejectionv of`the v'case by suitableknown means (not shown) is effected. ADuringsubsequent forward movement e of thev breech block i4,a newcartridgasuch as the one indicatedat 2a,.is pushed vforwardlyintothechamber..A 'rhenringmechanismhaving been retracted during theexcursionl of the b oltrthe gun has been completely-and-'automatically-reloaded and-upon release of. the firing mechanism,whether automaticallyror by Aanother-pull offthe trigger, the arm willagain,"A fire and the cycle be In the form shown in Figs. ..3 Ato 7inclusive,;the numeral 2l represeutsthe barrelv threaded tothe receiver23 as at 2lc. The barrel is `formed with I a chamber 2la,.vaportionoffwhich 2lb, is reduced,

in externaldiameter. The lchamber is closed by .means of a Vbreech block24 shown as-attached to la tube 24a .slidably mounted in a passage .23ain the receiver.. V'.l'hisrpassage may be either round .or rectangulanasthe bolt 24 and tube 24a are -not adapted to rotate.

25 indicates aliandler sil-dable in a slot 25a` in the side of' thereceiver.v This handle may be used to-;operate. the action manually whende- .'sired4 @11d may Y also serve .l the purpose ofpreventfingrotationf ofthe bolt. -Theforward end of the 'vbolt124 isprovided-with lugs 2liv and 26a. Y

The; reduced-- expandible portion 2lb of the chamber. issurrounded by acollar 21 fitting .loosely Ythereonand connedY axially between a Yflugshav'eamcorresponding helical form. Connected with said passages 29a areentrance passages 29b located generally horizontallyisee Figs.

..4.and 6).l

InV the form shown, the action spring 3,0 is located in the receiverwith its forward end within the tube 23a, which spring tends to push thebolt forward tightly against the `head of the cartridge 22 within thechamber.

It will be noted that the helix angle of the passages 29a and the facesof the lugs 26 and 26a is so .great that axial movement of the bolt willcause rotation of the collar 21, 29. It will there` fore be notedthat ifthe handle 25 is pulled rearwardly, the lugs 29 and 26a will causerotation of the collar v21, 29 clockwise, as viewed from the rear, to anextent of 90 in the form shown, at which time the entrance passages 29halign with said lugs, and the bolt may be freely drawn rearwardly.During this time the unred cartridge in the chamber, if any, isextracted by means of any suitable extractor carried by the bolt 24(shown in cross-section and indicated by the numeral 24h in Fig. 5).

-If the gunis closed-with va cartridge 22 in the chamber and the 'firingmechanism' (striker or firing pin) is a'ctuatedthe cartridge will beexploded,:r'esulting in 'a powerful rearward thrust the reduced#chamberf portion '2lb' i's Vslightly expanded,grasping-.thee'col1ar`12'1"and holding'it against rotation." It' will.-thereforefbe impossible for the lugsito'move rearwardlyfand the boltwill remain in closedl position. until 'the gas pressure has dropped toa predetermined value,v` such as that represented by theline H inFig.'2.' When tion through 90 of the collar 21, 29,.,thus locat;

ing the entrance passages 29h vertically, permitting the lugs 26, 26a,to pass rearwardly,

.whereby the bolt 2t and its carrying tube 24a may move rearwardly .thefull distance (somewhat greater than the length of the cartridge),

z :while storing energy in.the compression of spring 30. v 1

' Immediately thereafter, the bolt are pushed forwardly, pushing thenext cartridge 22a f upwardly and forwardly v-into the chamber. In theform shown, the bullet passes up through the entrance slot 2,917.'- Whenthe bolt has almost reached its forward limit of movement, the lugs A26, 26a, pass in throughthe entrance slots 2lb until their forward edgesstrike the helical front surface of the passageA 29a, rotating thecollar 21, 29 counterclockwise, as viewed'from the rear. thus closingthe action,Uy f

The numeral 3l designates a plunger biased upwardly by spring 32 and`bearing normally in a `recess 21a in the collar 21'. It Ywill bev.noted from Fig.'7, thatthe plunger doesnot normally` enter fullywithin -recess21a but vbears only on one side thereofso as `tortend torotate --the collar 21 counterclockwise, as viewed from 4the rear. Thisserves to take up. any slack which might be present'rbetween-thehelicalfaces. of the lugs 24 and 26a.-.and': the .helical passage 29a, .andwill also serve-to -assure that the collar 21 will be pressedirmly`against abutment shoulder. 28.

This construction assures minimuml head space and play. l The collar214s formed-withanother depression 2-1-b slightlymore than .90? fromthe-depression 21a. When the gun isfopened,whe'therfby' hand or .as aresult of firing; depression 21h aligns with the plunger Il and'assuresthat the collar 21, 29 will be held in proper position-so thaty theentrance openings 29h will be vertically arranged and in properalignment with the lugs 2l, 26a.

Any suitable nring mechanism may be employed such as a striker II biasedforwardly by a spring (not shown). The rear end of said striker is shownas formed with an arm It with which is engageable the hook 31 of a scar99 biased clockwise by spring 39. The sear is shown as provided with apin 38a with which engages a shoulder 49a on a disconnector bar 4Ipivotally connected at 4la with the trigger 4I. Trigger spring 42 servesto rock the trigger clockwise. The disconnector bar 49 is shown ashaving an upwardly extending finger 40h lying in the path of a part ofthe breech block tube 24a. Aswill Vhelical surfaces on be readilyunderstood,

position even though the shooter continues td.

hold the trigger retracted. Therefore, as the breech block is pushedforwardly the hook 31A engages with the arm V36 and holds the strikerback in position ready for firing the next cartridge.'

Operation If the magazine, which may be a boxmagazine, tubular magazine,cartridge belt, or cartridge drum, is filled with cartridges andthepeint. r, nemeiy, after abeutrz units it' handle 25 drawn rearwardly,the collar 21,' 281' will rotate clockwise about 26, 26a, and permittingthe breech block to be retracted the full limit of its movement againstthe action of spring 30. Thereupon, by usual means, the first cartridgein the Vmagazine is placed in position for insertion into the chamber.By releasing handle 25, this cartridgeis pushed forwardly into thechamber. During this movement, the lugs 26, 26a pass 'through the nowvertically disposed thereuponl rotate the collar 21, 29about 90 counterclockwise, due to the coactioriof the the lugs and on the collar 29.. Asthe bolt reaches its forward limit of movement with its face against thehead of the cartridge in the chamber, the plunger 3i snaps into recess21a, thus rotating the collar 21, 29 slightly counter clockwise,assuring that the collar 21 bears firmly against abutment and that thecollar 29 bears firmly against the rear faces of lugs 26, 26a, thuseliminating play and excessive head space.

If the trigger is now pulled, the striker I6 is released and thecartridge exploded. This immediately causes a slight expansion of thethin section 2lb of the chamber, thus holding the collar 21 againstrotation, As a result of which, .lugs 20, 26a cannot move rearwardly andthe action remains closed. until the gas pressure has dropped to a,predetermined point, say that represented by line a-a in Fig. 2, i. e.,at the tridge represented by point, the chamber the full line curve. Atthis part 2lb contracts, freeing collar 21 which now rotates about 90clockwise under the thrust of the remaining gas pressure, thus freeingthe breech block for its'rearward excursion, during which extraction andejection occur. On its forward excursion, the breech block pushes thenext cartridge into the chamber, the bullet thereof in the form shownpassing up through-one of the entrance slots 28h. As the breech blockreaches its. forward limit of movement, the collar 21, 20 is againrotated counter clockwise about 90 to its normal locking position. Thiscycle of operation can of course be repeated as ions as cartridges areavailable in the magazine.

In addition to its great simplicity and cheapmessen advantage ci thisconstruction is that the gun willl reload reliably even in spite ofvariations inl/the power of the ammunition used. It s well known that itis very difficult to load :artridges uniformly and that even though thiss accomplished the cartridges will, upon long ztorage, deterioratethuscausing unequal gas nessures.

entrance passagesA 29h andv This condition continues point y for thenormal car-.-

90", releasing the lugscurve of a normalcartridge whereas ythe dottedIlines represent respectively the pressure-time curve of low powered andhigh powered car" tridges. Assuming that the gun in question is setto"open at a pressure of 1,000 units, when the normal cartridge is usedthe opening will occur afte'iabout 33 units of time. If, however, a weakcartridge is used, the gun opens at the of time ami with a powerfulcartridge the gun opens at t'.

namely, after about 39 units of time. As the gas pressure when the gunopens is the same irrespective of the power of the cartridge. it isobvious that the same pressure and forcewiii.

available to operate the action. rectly contraryto the experience withgas cpei- This iS ziiated guns which open earlier for high powercartridges and later for low power cartridges,

the direct opposite of the desired action.

Another form illustrative of the invention is shown in Figs. 8, 9, and10, wherein the breech closing mechanism is of the rotary bolt type. Thebolt may be similar to that of any high powf-erbit action rifle, such asthe Springfield model 'l being slightly greater man againstrotationjbyexcessive gas pressure.

bolt may be carried, as shown, by a tubular `member Bla'within which theforming an integral part of the 'of `lsiltwith the exception that'however in that itV 'of th'e boitbut has ,extensions 51a and 51h which4employed' to hold the collar 51 'due' to the helical vsurfaces and thecooperating lugs 55 the lug facce `and "their crd-acting abutmentswithinthe re ceiv'er'are of helical conformation, the helix angle the angle ofrepose.

In the forni shown the barrel 2| may be of the vsaune construction asthat shown in Figs. 3v and 4; The chamber supporting collar 51 diiersdoes not support the thrust co-act with and prevent rotation of the lugs50 and 56a of the bolt 54 when the collar 51 is held The action spring5l normal position 53h, preferably receiver 53. A 32 is preferably inits desired rois'housed. vThe bolt lugs are in locatedbetween lugs 53aand plunger 3,! actuated byspring inFigs. `3 "to 7' inclusive, theplunger preferably rests within its depressions in such a way as toVeliminate play between the extensions 51a and 51h and the lugs 5l and56a. Y operation Whenilring occurs, the rearward thrust against thevbolt 54 tends to cause rotation of the bolt on the rear lug faces 53a inthe receiver. However, rotation is Vprevented by the extensions 51a and61h ofthe collar 51, which is held in place by the expansion of thechamber. The breech therefore remains closed until the gas pressure'drops to a point where the chamber portion 2lb contracts. freeing thecollar 51 and permitting the' action to open. During this'time, thecollar 51 is rotated about 90. On the rearward excursion of the bolt,extraction and ejection occur -by usual means not shown and on thereturn stroke, the nextcartridge 22a is pushed into the chamber, thebullet thereof being moved forwardly `and upwardly through the spacebetweenv extensions 51a and 51h which are now arranged generallyvertically. When the bolt is almost home, the front faces of lugs 56 and56a strike cooperating inclined surfaces 53h on the receiver, thuscausing rotation of the bolt to its Y Fig. 2 indicates in full line thepressure-time 75 locking position, carrying collar 51 along. The

gun is now ready to be fired again, which cycle desired, ,YAs'guns.ofithis type frequently-'a nicmdinwsi 10" ycharmer',portion"islikely to becomejheafted toa likewise," Ha, f not tothe saine.temperature in expansion of the chamber relative to the collar thispossible 1 diiiicult'y, itis proposed tomakefthe supporting emcient ofexpansion plunger 2 Iy 'i'ormed'as atube of may be repeated indefinitelyas long as ammunition is available. The dimensions of the reducedchamber section as shown in the drawings are not intended to be accuratefor al1 purposes.` The wall thickness would be computed according to thepower of the cartridge and the' gas pressure at which opening timesin'duick'. succession. the barrel rather high. temperature. 21, or 5 1wi llalso become heated but probably mamme result to an undesiredextentg. To V`overcome 'chamber portion;

porting member, whereby the breech closing member is held closed untilafter the gas pressure has dropped sufciently low to permit contractionof the weakened chamber portion.

2. In a firearm, a barrel having a cartridge receiving chamber formedtherein, at least a part of the chamber portion of said barrel beingformed as a tube of such reduced thickness that the gas#cartridge-exploded in said-cham;

v'f''expanding' 'the' said reduced -`a="supp`o'rting collar closelysurrounding saidqdced portion, abreech closingmembenfandvme'an's.'associated with said supportcollar of a materialhaving.' ahlgher' thermal cothany the steel used for the barrel. Forthis purpose the use of certain stainless steels known to have aefllcient is contemplated. 4

Fig. T11 is a cross-section throughithe ychaxirber of a gunot any of theillustrated ing a modified iormff .Instead'of depending upon ytheexpansionof the chamber tofg'rip -the-supporting collar A(as Ma, 21,

wall 2li may be made considerably thicker and* the supporting collarllzsomewhat thinner. The chamber` wa1l'2l:r is perforated to receive ahaving its endsformed concentric with the barrel bore.' When the gun isfired, the

plunger 2W will be shifted very slightly, its outer end being thrustagainst the collar A21x and holding it against movement until the gaspressure 'subsides to a certain value. If desired. the plunger may beformed shouldered as shown with a washer Ilz of rubber or the like toprovide slight resiliency and to assure proper sealing.

It vwill be noted that in the forms shown in Figs. 3 to 10 inclusive,the thrust on the block 24 or bolt 54 can cause rotation of the collaronly through a negative me- 'chanicaladvantaga this being due to thefact that the helixangles are so chosen as to be only slightly greaterthan the angle of repose. lI'herefore, only-a slight gripping of thecollar by theexpansible chamber will suiiice to prevent opening of theaction; It is, of course, to be understood that various 'supplementaldevices may be used. such as safety devices, single shot orautomatic-fire firing mechanism, means for holding the action open whenthe magazine is empty, barrel cooling means, etc.

The invention is not intended to be limited to the several forms o!construction shown, which are to be understood as illustrative only andnot las limiting as various changes in construction and arrangement maybe made, it being intended that the patent shall cover -by suitableexpression in the appended claims all features of patentable noveltyexisting in the invention disclosed.

I claim:

-l. In a flrearm, a barrel having a cartridge receiving chamber formedtherein, at least a part of said barrel being such reduced thicknessthat of the' chamber: portion a cartridge exploded in saidv ingmemberpreventing .opening 'of the breech closing member while thereduced-chamber porft'ion isfei'c'pandedagainst said supporting collar.whereby' :the-breech; closing member is held closed :until after the gaspressure Vciently low` to 20' high expansioncohas dropped suillpermitcontraction of the weakened chamber portion and'freeing of said collar.

13.fIn a `firearm, a barrel having a cartridge receiving chamber' formedtherein, at least a part"v ofthe chamber portion of said barrel beingformed as a'tube of suchreduced thickness"thatv thevgaspressurey of'acartridge exploded in said chamber z is capable of expanding vthi? .saidreduced/chamber portion,.a rotatable supporting collar closelysurrounding said. :reduced portion, abreech closing member, zand meansassociated with said rotatable supporting collar preventing opening ofthe breech closing -member without rotating said collar, whereby thebreech closing member is held closed until after the gas pressurehas'dropped sufficiently low to permit contraction of the weakenedchamber portion and rotation of said collarr- 4. In a firearm, a :barrelhaving a cartridge receiving chamber formed therein, .at least a part ofthe chamber portion of said barrel being formed as a ltube of suchreduced thickness that the gas pressure'ofa cartridgeexploded in saidchamber is capable of expanding the said re duced chamber portion-,a'rotatable Vsupporting collar closely surrounding said reduced portion.a non-rotatable breech closing member, and helical connecting means,between said breech closing member and said collar whereby the breechclosing member is held closed until after the gas pressure has droppedsufficiently low to permit contraction of the weakened chamber portionandrotationof said collar.

5. In a firearm, a barrel having a cartridge receivingchamber formedtherein, at least a part ofthe chamber portion of said barrel beingformed as a tube of such reduced thickness that the gas pressure of acartridgev exploded in said chamber is capable of expanding the saidreduced chamber portion, a receiver, a rotatable supporting collarclosely surrounding said reduced portion, a rotatable breech closingmember, and helical connecting means between said breech closing memberand said receiver, means connected with the supporting collar forpreventing rotation of said breech closing member without rotating saidvsupporting collar, whereby the breech closing member` is held closeduntil after the gas pressure has. dropped sufficiently low to permitcontraction of "the weakened chamber portion and consequent rotation ofsaid collar and said rotatable ,breech closing member. v

6. The combination according to claim 3 including detent means forholding the supporting collar in its normal rotative position.

y'7. The combination according tovclaim 4 including detent means forholding the supporting collar in its normal rotative position.

8. The combination according to claim including detent means for holdingthe supporting collar in its normal rotative position.

- 9. The combination according to claim 3 lncluding detent means forholding the supporting collar either in its normal position or in thebreech openable position.

10. The combination according to claim 4 including detent means forholding the supporting collar either in its normal position or in breechopenable position.

ll. The combination according to claim 5 including detent means forholding the supporting collar either in its normal position or in breechopenable position. v

12. The combination according to claim 3 including detent means forholding the supporting collar in its normal rotative position but biasedto closed breech position.

13. The combination according to claim 4 including detent means forholding the supporting collar in its normal rotative to closed breechposition.

14. The combination according to claim 5 including detent means forholding the supporting collar in its normal rotative position but biasedto closed breech position.A

l5. In a firearm, a barrel having a cartridge receiving chamber formedtherein, at least a part of the chamber portion of said barrel beingformed as a tube of such reduced thickness that the gas pressure of acartridge exploded in said chamber is capable of expanding the saidreduced chamber portion. a breech vclosing member formed with a collarclosely surrounding said reduced portion, whereby the breech closingmember is held closed until after the gas pressure has droppedsuilciently low to permit position but biased contraction of theweakened chamber portion and freeing of said collar.

16. The combination according to claim 1 in t which the supportingmember is made of a material having alhigher co-eilicient of thermalexpansion than the material oi' said chamber.

l'l. In a iirearm, a barrel having a cartridge receiving chamber, atleast a portion of the chamber being of such reduced thickness that thegas pressure of a cartridge exploded in said chamber is capable ofexpanding the said reduced chamber portion, a supporting member closelysurrounding said reduced portion, said reduced chamber portion and saidsurrounding member being normally relatively movable, a breech closingmember, and means so associated with said supporting member that openingof the breech closing member will cause relative movement between thesurrounding supporting member and the reduced chamber portion, wherebyopening of the breech closing member is prevented while the reducedchamber portion is expanded against said supporting member so that thebreech closing member is held closed until after the gas pressure hasdropped suificieitly low to permit contraction of the weakened chamberportion.

18. In a ilrearm,la barrel having a cartridge receiving chamber, atleast a portion of the chamber being of such reduced thickness that thegas pressureof a cartridge exploded in said chamber is capable oiexpanding the said reduced chamber portion, a supporting member closelysurrounding said l`reduced portion, said reduced chamber portion andsaid surrounding member being normally relatively rotatable, a breechclosing member, and means so associated with said supporting memberAthat opening of the breech closing member will cause relative rotationbetween the surrounding supporting member and the reduced chamberportion, whereby opening of the breech closing member is prevented whilethe reduced chamber portion is expanded against said supporting memberso that the breech closing member is held closed until after the gaspressure has dropped suiiiciently low to permit contraction oi theweakened chamber portion.

ALLEN A. DICKE.

